As opposed to other wave forms, a sine wave of 10 kHz does not contain any signal at a frequency other than 10 kHz.

That means, in theory you will get rid of all noise and distortion if you have an ideal band pass filter designed for 10 kHz. In the real world, however, this filter will be far from ideal, but still it will the dominant contributor to the total noise and distortion.

I think you need a high Q double T network or something like that... but I have good results with a diy oscilator (0.004% THD).. it's a simple wienbridge with a 3.5 watt/220 lamp and a NE5534 ... it's at 1KHz, but 10KHz should be possible of course, perhaps even with lower distortion...

Goodluck,
Thijs

PS
You can check the www.sound.au.com for the 'feed-forward' oscilator.. maybe you can improve on it.. I've been wanting to do that for some time now but haven't started yet..